Electric grinder



April 1953 H. SKREBERG 2,636,323

ELECTRIC GRINDER Filed Feb. 7, 1952 jkwmzaif yuan Patented Apr. 28, 1953 UNITED ELECTRIC GRINDER Hans Skreherg, Big Bend Township, Chippewa County, Minn.

1 Claim. 1

The object of my present invention is to provide an electric grinder having advantages over conventional grinders, one being a horizontally rotatable grinder spindle assembly that can be rotated the full 360 of a circle. Another advantage is a vertically arranged motor that has its case connected to the said grinder head assembly by means of a tube, hence the motors case can be rotated in unison with the grinder head assembly, eliminating all reactive force between the motors armature shaft and the upwardly extending extension shaft having a bevel or mitre gear that engage a mitre gear or pinion on the horizontally arranged grinder wheel shaft.

By providing a means for locking the grinder spindle at any point of its horizontal travel from zero to quarter, half, or other fractional movement that it may be desirable to position the grinder spindle, grinding of long bars, sickles, etc., is possible without moving the machine, or that might otherwise require placing the grinder at a distance from a wall or other obstruction that would interfere with working space in the shop where other machines are installed and used by the workman.

Other advantages, such as quick removal of grinder spindle by removing the four bolts that secure the grinder spindles four journals to the tubular extensions of a T-member that forms the attaching medium of said tubular extension members to the vertical tubes upper end, for the purpose of substituting saws or other tools for the grinder head, attaching a table to the tubular extensions, etc., converts the grinder to a wood-working or other purpose machine.

In Fig. 1 in the drawing I represents frame members secured to a top member 2 and a platform member 3, forming a square stand with outwardly sloping legs extending below the platform member 3. An electric motor having on its bottom end of the case a centrally located pivot 2| engaging a circular hole 22 in the central part of the platform member 3, the top end of the motor case 4 is connected by studs 5 and plate 6 with a tube 1, the said tube 1 extending upwards and beyond top face of the frame member 2 through a central hole in said frame member or cap 2, and the extreme upper end of tube 1 has a T- member 8 and tubular extensions 9.

Journals 19 are secured to tubular extensions 9 by means of bolts H, and journals carry the horizontal shaft 12 to which gear 13 is secured.

The shaft 14 connected to motors armature shaft end by flexible coupling 1' extends upwards inside the tube 1 and has the gear l that forms the drive for gear l3 of shaft l2 which has the grinding wheels 16. A clamp 11 in connection with the member 18 forms a locking device for the tube 1 and the T-member 8.

The electric power circuit (preferably the positive side) is connected to insulated collar l9 which is mounted on tube 7 by means of brush 20. Collar I9 is in turn connected by cable l9 to motor terminal l9". The ground or negative side of the circuit is connected to the frame which connects through plate 3 directly to the motor case.

Like numbers designate like parts in Figs. 1, 2 and 3.

I claim:

In combination with a frame comprising a square top member having a centrally located hole and downwardly extending members having a platform with a centrally located hole, said platform located intermediate top member and lower ends of downwardly extending members, an electric motor pivotally mounted on said platform, the upper end of the motor case connected to the lower end of an upwardly extending tube by means of studs and a plate, a T-member secured to the extreme upper end of said tube above the top face of said top member of the frame, tubular extensions extending horizontally in opposite directions from the T-member, a plurality of journals attached to the tubular extension members by bolts, a shaft in said journals arranged parallel to and above said extension members, said shaft having a mitre gear or a bevel pinion adjacent to T-member, means for mounting grinding wheels at ends of said shaft, and upwardly extending shaft inside the tubular member connected to end of motors armature shaft by means of a coupling and having at its upper end a gear engaging gear on the horizontal grinding wheel shaft, an insulated brush collar secured to tubular member above the end plate at lower end of the vertical shafts plate member, a brush engaging said brush collar, a cable from the brush collar to motors terminal, and a cable from brush to source of electric current, a ground-side cable from motors pivot platform, a clamp surrounding the T-member and means for locking said clamp.

HANS SKREBERG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,412,715 Siefertson Apr. 11, 1922 2,239,639 Amidon Apr. 22, 1941 2,288,579 Anesi June 30, 1942 2,458,840 Eklund Jan. 11, 1949 FOREIGN PATENTS Number Country Date 230,803 Great Britain June 19, 1930 

